Attachment for rotaries



H. G. JOHNSTON. ATTACHMENT FOR ROTARIES. APPLICATION FILED MAY 28, 1919.

Patented July 20, 1920.

2 SHEETS-SHEFT I.

H. G. JOHNSTON. ATTACHMENT FOR ROTARIES. APPLICATION FILED MAY28, 1919.

.m Ow w m l 1H 0 1 mm J 100V). m m m P P UNITED STATES PATENT' OFFICE.

HORACE G. JOHNSTON, or CORSICANA, TEXAS, ASSIGNOR T0 GENEVIEVE JOHNSTON,

0E GOESICANA, TEXAS.

ATTACHMENT FOR BOTARIES.

Specification of Letters Patent.

Patented July 20, 1920.

Application filed May 28, 1919. Serial No. 300,459.

To all whom it may concern:

Be it known that I, HORACE G. JOHNSTON, a citizen of the United States, residing at Cor'sicana, in the county of Navarre and State of Texas, have invented certain new and useful Improvements in Attachments for Rotaries; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to rotary well-drilling machinery and has for an object to provide an improvement in a rotary, such improvement being an improvement on the improvement shown in my Patent No. 1,135, 808, dated April 13, 1915.

In the aforesaid patent the ring or bush- 1 ing through which the pipe or string was inserted through the rotary table was pro- 'vided with means for holding such ring or bushing stationary relative to the table and to rotate therewith. In practice it is found desirable to permit this ring or bushing to rotate independently of the table and the present invention is directed to means for accomplishing the rotating effect.

With these and other objects in View the invention comprises certain novel constructions, combinations and arrangement of parts as will be hereinafter more fully described and claimed.

1n the drawings, I

Figure 1 is a top plan view of a conventional rotary with the bushing attachment applied thereto.

Fig. 2 is a diametrical sectional View through the rotary. Fig. 3 is a top plan View of the rotary table with the gripping mechanism removed and the ring or bushing shown with a part broken away.

Fig. 4 is an inverted plan view of the bushing.

Fig. 5 is a view of the bushing in side elevation.

Fig. 6 is a perspective View of one of the segmental wedges inserted between the bushing and the pipes.

Like characters of reference indicate corresponding parts throughout the several views. I

As inPatent No. 1,135,808, 10 indicates the rotating table having a ledge or shoulder 11 formed in the central opening by means of an enlarged opening 12 above said ledge.

portions or apertures 14 so positioned that when the bushing or ring 15 is inserted in the central opening of the rotating table 10 the flange 16 of such bushing will rest upon the ledge 11.

The ring or bushing 15 is provided with lugs 17, so positioned and proportioned that they will pass through the apertures 14 and engage under the ledge 11 thus leaving the bushing 15 free to rotate with the lugs 17 engaged under the ledge 11 and to prevent the withdrawal of the bushing from the retary table except when such lugs 17 are in registry with the apertures 14.

' Into the bushing 15 the segmental wedge members 18 are inserted as indicated more particularly at Figs. 1 and 2, such segmental wedge members being shown in perspective as Fig. 5 showing the teeth or serrations 19 upon the inner face thereof which will grip the pipe or string 13.

In unscrewing the several lengths of the string it is found necessary that the bushing revolve and at the same time it is desirable to prevent the bushing from being lifted out of the table. In Patent No. 1,135,808 the lifting of the bushing was prevented by means of buttons which, however, are not necessary in view of the fact that in the present application lugs pass below ledge 11 and can be lifted out of the table only when such lugs register with the openings each other until the lugs 17 register with the apertures 14 when the bushing may be lifted out. Practically at all times in the actual operation of the device the lugs 17 will not come into registry with the apertures 14 and will, therefore, serve at practically all times to prevent the lifting of the bushing from the rotating table.

It will be understood that the present invention has its utility in drawing the pipe or string from the well wherein when the pipe is drawn up by the derrick the wedges automatically drop into gripping position and engagement with the pipe to prevent the return movement of the pipe, permitting the unscrewing of the sections of the pipe or string while supporting that'portion of the string below the rotary and in the boring.

I claim:

1. The combination with a rotary table having a central opening of an inwardly extending ledge formed therein with an aperture formed therethrough, a bushing proportioned to be inserted through the opening and having a flange proportioned to rest upon the ledge and means formed upon the bushing proportioned and positioned to pass through said aperture and engage under the ledge and prevent the Withdrawal of the bushing from the central opening ex cept when said aperture and means register.

2. The combination with a rotaryjta'ble.

having a central opening therein, of a bushing adapted to fit into the central opening and to rotate relative thereto, and means carried by the bushing to engage under the rotary table.

3. The combination with a rotary table having a central opening provided with radially extemling'cut-out portions, a bushing proportioned to be inserted into the central opening and rest upon the table free to rotate with respect thereto and members carried by the bushing adapted to pass through the radially extending cut-out portions and engage under the rotating table.

In testimony whereof I aflix my si nature.

Homer: e. Jon'NsioN. 

